The present invention relates generally to a system for surveying land and, in particular, to an apparatus for gathering and displaying information concerning the contour of land.
Agriculture and construction businesses often require the measurement of the contours of land to obtain information for the leveling of ground for fields or construction sites. For example, a farm field must be contoured so as not to retain surface water which will stunt the growth of and/or damage crops. Therefore, the contour of the field must be measured in order to determine whether dirt must be moved and, if it must be moved, how the least amount of dirt can be moved in order to accomplish the desired grading.
One prior art method of contour measurement was to mark the field in a grid system of rows and columns. For example, a white-colored, sand filled bag would be placed at the intersection of rows and columns on the field, typically at intervals of 100 feet. Then surveying instruments would be utilized to determine the elevation of the marked grid points with respect to a reference or entering point in the grid. The use of the well known surveyor's tripod-mounted sight and stick required the effort of two persons and considerable time in moving the stick from grid point to grid point as marked by the bags.
An improvement in this method of contour measurement was achieved through the use of a laser beam transmitter mounted at a reference point and a receiver mounted on a vehicle which could be driven from grid point to grid point. At each grid point the driver of the vehicle would mark down the reading from the receiver such that only one operator was required and the total time for taking the measurements was considerably reduced.
Either of the above-mentioned methods of measuring the contour of the land required considerable calculations to determine the most efficient distribution of dirt and how much dirt actually had to be moved. Once the dirt movement process had begun, there was no way to check the resulting contour without performing a new survey which required additional time and expense.
Among some of the problems associated with the prior art methods are the inaccuracies due to the movement and resetting of the measurement apparatus and the laborious calculations involved in determining the most efficient movement of the dirt. Additionally, since the cost of the operation is usually based on the amount of dirt moved, the land owner is at the mercy of the person making the calculations.